Blank firing barrels for semiautomatic pistols and method of repetitive blank fire

ABSTRACT

The present invention embodiments provide a barrel component with the forward under-portion of the barrel configured in various manners. For example, the configurations may include an upward displacement, or angular or radial contouring, of barrel material at the forward underside of a barrel component understation or projection. These configurations provide clearance to allow the barrel to bypass frame-mounted impediments to blank-fire, and permit proper timing and coordination of rearward barrel motion under impact of the recoiling slide and the resultant barrel drop into recoil position without interference with, or re-capture by, the reciprocating slide component. In addition, the blank-fire barrel may be configured to incorporate a laser device for marksmanship training and conducting realistic tactical training exercises.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from U.S. Provisional Patent Application Ser. No. 60/905,033, entitled “Blank-Firing Conversions for Semiautomatic Pistols and Method of Repetitive Blank Fire” and filed Mar. 6, 2007, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention embodiments generally pertain to firearms. In particular, the present invention embodiments pertain to semiautomatic breech-locked, recoil-operated pistols configured to produce reliable and repetitive blank-fire operation.

2. Discussion of Related Art

Conventional semiautomatic pistols designed to discharge high-pressure cartridges (e.g., 9 mm Parabellum, 0.357 SIG, 0.40 S&W, 10 mm, and 0.45ACP cartridges) typically employ a breech-locked, recoil-activated mechanism that is derived from the BROWNING and COLT/BROWNING family of firearms. In this mechanism, the pistol barrel and slide are locked together and collectively travel rearward for a predetermined distance in response to firing of a projectile or bullet to initiate a firing cycle. The firing cycle is automatically performed from the recoil energy and typically includes: opening of the pistol breech after firing the shot; extraction and ejection of an empty cartridge shell; cocking of the pistol hammer; presentation and introduction of a loaded cartridge into the pistol barrel; and closing of the pistol breech. The design of the recoil-activated mechanism has evolved and is employed by various pistols (e.g., those produced by BERETTA, GLOCK, HECKLER & KOCH, SIG-SAUER, and SMITH & WESSON).

In accordance with this design (and variants thereof), safe discharge of the cartridges is accomplished by delaying opening of the pistol breech mechanism (and subsequent extraction of a fired cartridge case from the barrel chamber) until the fired projectile or bullet has exited the muzzle. This relieves the high-pressure gases contained within the barrel bore that would otherwise cause catastrophic rupture of a partially extracted case lacking support of a surrounding chamber enclosure. In order to provide the breech-opening delay, the pistol barrel and slide are locked together by a mechanical mechanism, and recoil in unison for a predetermined distance until a safe level of pressure is achieved subsequent the bullet's exiting the barrel. At this point, the barrel and slide are separated through the interaction of a supporting frame abutment that engages a provision at an underside of a barrel element, thereby drawing the barrel from a locked battery position and allowing rearward travel of the slide. The slide rearward motion effects extraction and ejection of the fired cartridge case, and maintains the barrel in a proper recoiled position to receive a fresh cartridge from a pistol magazine. These operations occur as a result of the moment of inertia generated by the mass of the moving projectile or bullet, rather than by the mere gas pressure generated. Examples of these effects are disclosed in U.S. Pat. Nos. 5,433,134 (Leiter), 5,585,589 (Leiter) and 5,675,106 (Leiter).

In order to provide reliable and repetitive blank-fire in these types of firearms, modifications to the barrel may be provided beyond the presence of a bore-restricting or occluding element that generates back pressure within the bore to produce recoil. These modifications to the barrel remove or modify interference by the breech-lock provision, and compensate for consequent ungoverned and un-timed barrel motion imparted by the slide as the barrel is forced rearward under recoil. An example device for overcoming the breech-lock obstacle that ordinarily hampers blank-fire operation is disclosed in aforementioned U.S. Pat. No. 5,433,134 (Leiter). In addition, rearward displacement of a portion of the rearward underside of the barrel element may be provided to permit free barrel drop into recoil position absent the presence of a timed breech-lock feature, while still allowing engagement of the barrel element by the appropriate frame-abutting element of a pistol receiver. An example of this type of displacement is disclosed in aforementioned U.S. Pat. No. 5,585,589 (Leiter). The Leiter patents discussed above (U.S. Pat. Nos. 5,433,134; 5,585,589; and 5,675,106) are incorporated herein by reference in their entireties.

However, certain other obstacles may persist within these types of breech-locked firearms that hinder or prevent repetitive blank-fire. These obstacles may arise within pistol designs containing a particular disposition of the battery-indexing element of the frame. An example of this type of obstacle may be present within the H&K USP-series and the H&K P2000-series pistols. The obstacles may further arise within pistols incorporating improvements, altered geometries or dimensional changes in frame design affecting the battery-indexing element, where the alterations often occur for the purpose of strengthening the area surrounding or abutting the battery-indexing provision. An example of this type of obstacle may be present within the Third Generation of GLOCK pistols.

In the case of each of these obstacles, the design factors impose additional surfaces or material within the frame at the forward portion of the barrel underside critical for blank-fire operation. Further, the frame-mounted projections described above serve to establish a stop point for the barrel and slide when assembled on the frame, and define their locked, in-battery position on the frame. Consequently, a barrel drop into the recoil position is impeded by the presence of forwardly extended frame material (or by a counterpart in another frame-mounted component), and blank-fire cannot be effectively achieved since the barrel cannot clear the impediment that blocks the barrel drop and the continued rearward motion of the slide. Thus, even though the slide no longer contacts the corresponding locking element of the barrel upon discharge (e.g., as disclosed in the aforementioned Leiter patent (U.S. Pat. No. 5,433,134)), it cannot draw the barrel immediately or sufficiently to the rear to bypass the forward areas of the frame that support and hold the barrel in battery position.

Moreover, regardless of the force the slide imparts to a barrel with breech-lock modification under blank-fire (e.g., refer to the aforementioned Leiter patent (U.S. Pat. No. 5,433,134)), the barrel cannot achieve sufficient velocity to clear the forward frame or frame-mounted element and is re-captured by the reciprocating slide, thereby preventing downward barrel motion through interaction with the rearward frame abutment/support element. This prevents proper timing of barrel motion, drop, and clearance from the reciprocating slide. Since the modified barrel begins motion from a state of rest while the slide has already accelerated under recoil, the barrel cannot gain sufficient velocity to exceed that of the recoiling slide and clear the forward frame abutments beneath the barrel.

SUMMARY OF THE INVENTION

Accordingly, the present invention embodiments provide a barrel component with the forward under-portion of the barrel configured in various manners. For example, the configurations may include an upward displacement, or angular or radial contouring, of barrel material at the forward underside of a barrel component understation or projection. These configurations provide clearance to allow the barrel to bypass frame-mounted impediments to blank-fire, and permit proper timing and coordination of rearward barrel motion under impact of the recoiling slide and the resultant barrel drop into recoil position without interference with, or re-capture by, the reciprocating slide component.

In addition, blank-fire operation may be enhanced to include laser targeting or laser signature capability. In particular, the blank-fire barrel may be configured to incorporate a threaded laser device. This capability is of particular value in law enforcement and military training usages, and commercial applications, where realistic firearm operation is afforded by blank-fire when laser-marking capability is available to replicate bullet point of impact. This affords both marksmanship training and the ability to conduct realistic tactical training exercises absent the inherent restrictions and dangers attendant with the use of live ammunition.

The above and still further features and advantages of the present invention will become apparent upon consideration of the following detailed description of example embodiments thereof, particularly when taken in conjunction with the accompanying drawings wherein like reference numerals in the various figures are utilized to designate like components.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view in perspective of an internal configuration of an example Heckler and Koch type pistol for use with a present invention embodiment.

FIG. 2 is view in elevation of a conventional barrel unit for the pistol of FIG. 1.

FIG. 3 is a side view in perspective of the internal configuration of the pistol of FIG. 1 including a blank-fire barrel unit according to an embodiment of the present invention.

FIG. 4 is a view in elevation of the blank-fire barrel unit of the pistol of FIG. 3 according to an embodiment of the present invention.

FIG. 5 is an exploded view in partial section of the blank-fire barrel unit of FIG. 4 configured to receive a laser device according to an embodiment of the present invention.

FIG. 6A is a side view in perspective of an example third generation GLOCK type pistol for use with a present invention embodiment.

FIG. 6B is a view in perspective of the frame of the example third generation GLOCK type pistol of FIG. 6A

FIG. 7 is a top perspective view of example second and third generation GLOCK type pistols for use with a present invention embodiment.

FIG. 8 is a view in elevation of a conventional barrel unit for the pistol of FIGS. 6A-6B.

FIG. 9 is a close-up view of a portion of the barrel unit of FIG. 8.

FIG. 10 is a view in elevation of a blank-fire barrel unit for the pistol of FIGS. 6A-6B according to an embodiment of the present invention.

FIG. 11 is a close-up view of a portion of the blank-fire barrel unit of FIG. 10.

FIG. 12 is an exploded view in partial section of the blank-fire barrel unit of FIG. 10 configured to receive a laser device according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An example Heckler and Koch type pistol 20 for use with present invention embodiments is illustrated in FIGS. 1-2. Specifically, firearm or pistol 20 includes a frame 1, a slide 2 mounted on frame 1, a barrel unit 3A, and a recoil spring mechanism 5. Frame 1 includes a trigger mechanism 18 with a hammer 16, and a handle or grip portion 19 housing a magazine 21 for storage of one or more cartridges 28. Slide 2 is mounted on frame 1 and is adapted for reciprocal longitudinal movement on the frame in response to firing of pistol 20. Barrel unit 3A includes a chamber portion 41A and a barrel portion 43A. The chamber portion underside or bottom surface includes forward understations or projections 9, 25 and a rear understation or projection 26. Projections 9 and 25 adjoin each other with projection 25 basically forming a shoulder (e.g., or non-planar geometry) with the bottom surface of barrel portion 43A, while rear projection 26 is separated from front projection 9 by a suitably dimensioned gap or recess 45. The barrel unit is slidable and tillable relative to slide 2, and is operatively connected to frame 1. Spring recoil mechanism 5 is positioned below barrel portion 43A, and returns slide 2 and barrel unit 3A to the forward battery position after recoil as described below.

The barrel unit and slide are locked together toward intermediate portions of those components. Pistol 20 typically includes a breech-lock mechanism in the form of a vertical abutment surface 29 of slide 2 engaging a vertical abutment surface 24 disposed on a top surface of chamber portion 41A. Abutment surface 24 basically forms a shoulder (e.g., or non-planar geometry) with the barrel portion top surface to engage abutment surface 29. The breech-lock mechanism collectively drives barrel unit 3A and slide 2 rearwardly to an appropriate position during recoil. Spring recoil mechanism 5 is positioned below barrel portion 43A and returns slide 2 and barrel unit 3A to the forward battery position after recoil as described below.

Normal live-fire indexing and maintenance of slide 2 and barrel unit 3A in a battery position is accomplished by a combination of recoil spring mechanism 5 and a barrel support 13. The barrel support includes lower and upper recesses 22, 23 respectively defined in barrel support top and bottom surfaces, and is removably affixed to frame 1 by a slide-stop latch pin 17 disposed within barrel support lower recess 22 above trigger 18. Forward understation or projection 9 of barrel unit 3A is disposed within upper recess 22 and abutts barrel support 13 to maintain barrel unit 3A in a locked in-battery position. Further, the combination of barrel unit 3A and barrel support 13 are fixed in their locked in-battery position by latch pin 17 contacting a rearward portion of barrel support lower recess 22 to prevent forward motion of the assembled elements (e.g., slide 2, barrel unit 3A, barrel support 13, etc.). Rearward motion of the assembled elements is precluded by contact of barrel support 13 with frame 1 adjacent spring recoil mechanism 5.

Upon discharge of pistol 20, barrel unit 3A and slide 2 (e.g., engaged by abutment surfaces 24 and 29 forming the breech-lock mechanism) move rearward, and rear barrel understation 26 clears barrel support 13. The barrel unit is further drawn downward by the engagement of projection 9 with barrel support 13 (e.g., projection 9 being disposed within barrel support lower recess 22) to provide fired cartridge extraction and ejection, and to be placed in position to receive a fresh cartridge housed within magazine 21 of handle 19. This interaction of elements is dimensionally timed to enable forward understation or projection 25 to clear barrel support 13 by the moment of barrel drop. Projection 25 basically bypasses a support surface 27 disposed between barrel support upper recess 23 and spring recoil mechanism 5 through the coordinated support of the bottom surface of rear projection 26, thereby permitting correct and unimpeded separation of the barrel unit from the reciprocating slide (e.g., disengagement of barrel abutment surface 24 from slide abutment surface 29). This rearward distance is traversed by barrel unit 3A to allow proper barrel drop, and for this to occur, immediate barrel unit motion accompanies initial slide motion.

Pistol 20 including a blank-fire barrel unit of a present invention embodiment is illustrated in FIGS. 3-4. Initially, pistol 20 is substantially similar to the pistol described above and includes a blank-fire barrel unit 32A. The blank-fire barrel unit is similar to barrel unit 3A described above and includes chamber portion 41A and barrel portion 43A. The chamber portion underside or bottom surface includes forward understation or projection 9, rear understation or projection 26 separated from front projection 9 by suitably dimensioned gap or recess 45, and an area 30 adjacent forward projection 9. The chamber portion top surface includes abutment surface 24. The blank-fire barrel unit includes various modifications to at least abutment surface 24, rear understation or projection 26 and area 30 as described below to enable and enhance repetitive blank fire.

Abutment surface 24 of barrel unit 32A is configured to obviate immediate contact between slide 2 and barrel unit 32A. In particular, abutment surface 24 includes a rearwardly inclined surface 33 angled in an approximate range of eight to fifteen degrees, and preferably ten to thirteen degrees, relative to a barrel unit longitudinal axis. This diminishes the effect of initial barrel unit/slide locking by enabling a predetermined distance of free travel of slide 2 rearward during recoil, thereby producing a delay between the slide rearward movement and contact with barrel inclined surface 33. For an example of this type of configuration, reference is made to the aforementioned Leiter patents.

Rear understation or projection 26 of barrel unit 32A is configured to allow for correct rear barrel drop. In particular, rear understation or projection 26 is configured with a shorter dimension by moving a forward most upwardly-angled surface 31 of the projection to the rear at an oblique angle, preferably approximating the angle configuration for projection 26 of barrel unit 3A of FIG. 1. This effectively increases the dimensions of gap 45 and shortens the projection contact with the frame, thereby reducing the time and distance necessary for barrel unit 32A to drop downwardly into the rearward recoil/cartridge feeding position. Consequently, the amount of recoil force required to drive the slide and barrel unit rearwardly is reduced. Preferably, understation or projection 26 is shortened (or gap 45 is lengthened) by approximately 25% to 75% relative to barrel unit 3A (e.g., includes a reduced length in the approximate range of 0.075 to 0.225 inches). For an example of this type of configuration, reference is made to the aforementioned Leiter patents.

The combination of angled abutment surface 24 and shortened understation or projection 26 (or lengthened gap 45) assists pistol 20 to operate in a repetitive automatic manner with the barrel unit dropping to a cartridge feeding position at the appropriate time sequence. Barrel unit 32A may further include a restrictor element or occlusion 47 disposed at any suitable location (e.g., proximal or distal end, intermediate portion, etc.) within barrel portion 43A to generate sufficient back pressure upon firing of a blank cartridge to drive slide 2 and barrel unit 32A rearwardly, while recoil spring mechanism 5 returns slide 2 and barrel unit 32A to the battery position as described above.

Since the immediate contact between slide 2 and barrel unit 32A has been removed by inclined surface 33 of abutment surface 24 as described above, no manner exists to permit barrel forward understation or projection 25 (FIG. 1) to clear support surface 27. Accordingly, the removal (or modification) of forward understation or projection 25 is embodied in area 30 (FIG. 4), where forward barrel drop and separation from the reciprocating slide is timed to bypass contact with support surface 27. By way of example only, area 30 of barrel unit 32A represents a barrel unit configuration with the removal of understation or projection 25. In this case, area 30 of chamber portion 41A is substantially flush (or planar) with the bottom surface of barrel portion 43A, and extends to a forward or front surface of projection 9. However, barrel unit 32A may alternatively include understation or projection 25 configured in any fashion to bypass support surface 27 (e.g., adjustment of any suitable projection dimensions).

Barrel unit 32A may further be configured to receive a laser device emitting a laser beam upon firearm actuation. This provides enhanced capabilities with respect to training and marksmanship applications. Referring to FIG. 5, barrel unit 32A is substantially similar to the barrel unit described above for FIGS. 3-4, and includes chamber portion 41A and barrel portion 43A. The chamber portion receives blank cartridge 28 (FIG. 3) and includes a bore area 49 to provide for expansion of combustion gases. The chamber portion underside or bottom surface includes forward understation or projection 9, rear understation or projection 26 separated from front projection 9 by suitably dimensioned gap or recess 45, and area 30 adjacent forward projection 9, each as described above. The chamber portion top surface includes abutment surface 24 as described above. The barrel portion includes a muzzle 37 disposed at a barrel portion distal end, and a receiving chamber 39 disposed proximally of muzzle 37 to receive a laser device 75 therein. Laser device 75 may be of the type disclosed in U.S. Pat. No. 6,322,365 (Shechter et al.), the disclosure of which is incorporated herein by reference in its entirety.

Solid occluding element or occlusion 47 is disposed between receiving chamber 39 and bore area 49. Occlusion 47 prevents passage of a projectile through barrel unit 32A, and further prevents combustion gases from reaching laser device 75 disposed within muzzle 37. The combustion gases may damage the laser device and/or propel the laser device from the barrel unit. The laser device housing and internal mechanism are housed within receiving chamber 39. The laser device housing includes threading 46 disposed about the housing distal end external perimeter, while corresponding threads 36 are disposed about the internal perimeter of muzzle 37. Laser device 75 is removably affixed to the barrel unit by inserting the laser device into receiving chamber 39 and engaging muzzle threads 36 with laser device housing threads 46. Receiving chamber 39 includes transverse cross-sectional dimensions (e.g., diameter, etc.) in the approximate range of 0.312 to 0.375 inches, and a depth sufficient to provide occlusion 47 with longitudinal dimensions of approximately 0.100 to 0.750 inches. The particular dimensions of receiving chamber 39 depend upon the size and design of the laser device. The longitudinal depth of muzzle threads 36 is approximately 0.250 to 0.500 inches, and depends upon the laser device geometries and the dimensional geometries of the barrel unit, where the combination of elements allows for the minimum occlusion dimension noted above. Further, muzzle threads 36 include a thread dimension and pitch matching that of laser device housing threads 46, and are preferably configured to include a thread dimension of approximately 7/16 of an inch with a pitch in the approximate range of 24 to 48 threads per inch. The particular specifications of thread dimensions and pitch are determined by the specific geometry of the laser device and the muzzle dimensions. In any case, muzzle threads 36 are configured to provide positive thread engagement without weakening the surrounding barrel unit material.

An example third generation GLOCK type pistol 40 for use with present invention embodiments is illustrated in FIGS. 6A-6B and 8-9. Specifically, firearm or pistol 40 includes frame 1, slide 2 mounted on frame 1, a barrel unit 3B, and a disassembly latch or slide lock 4. Frame 1 includes trigger mechanism 18 with a hammer (not shown), and handle or grip portion 19 housing a magazine to store one or more cartridges (not shown). Slide 2 is mounted on frame 1 and is adapted for reciprocal longitudinal movement on the frame in response to firing of pistol 40. Barrel unit 3B (FIGS. 8-9) includes a chamber portion 41B and a barrel portion 43B. The chamber portion underside or bottom surface includes a forward understation or projection 52 with a bottom surface 12, and a rear understation or projection 54. Rear projection 54 is separated from front projection 52 by a suitably dimensioned gap or recess 55. A front surface 60 of forward projection 52 includes an upper shoulder 62 formed with and disposed below a bottom surface of barrel portion 43A, a recess 64 defined in surface 60 below shoulder 62 and a lower projection 66A disposed adjacent recess 64. Lower projection 66A includes a front angled surface 14, and a bottom surface 68 substantially parallel with a barrel unit longitudinal axis. The lower projection bottom surface forms a front portion of bottom surface 12 of front projection 52. The barrel unit is slidable and tiltable relative to slide 2, and is operatively connected to frame 1. A spring recoil mechanism (not shown) returns slide 2 and barrel unit 3B to the forward battery position after recoil as described below.

The barrel unit and slide are locked together toward intermediate portions of those components. Pistol 40 typically includes a breech-lock mechanism in the form of a vertical abutment surface 56 of slide 2 (FIG. 6A) engaging a vertical abutment surface 11 disposed on a top surface of chamber portion 41B (FIGS. 8-9). Abutment surface 11 basically forms a shoulder (e.g., or non-planar geometry) with the barrel portion top surface to engage slide abutment surface 56. The breech-lock mechanism drives slide 2 and barrel unit 3B rearwardly to an appropriate position during recoil. The spring recoil mechanism (not shown) returns slide 2 and barrel unit 3B to the forward battery position after recoil as described below. Slide lock 4 further serves as the battery indexing provision that locks the barrel unit and slide in forwardmost firing position. Basically, the slide lock or disassembly latch (FIGS. 6A and 7) engages forward projection 52 (FIGS. 8-9) to position and hold the barrel unit in battery position within frame 1.

A comparative top view of second and third generation GLOCK type pistols 35, 40 is illustrated in FIG. 7. Pistol 35 includes corresponding frame 10, while pistol 40 includes frame 1 as described above. Third generation pistol frame 1 includes a frame buttress area 15A that is disposed at a higher location on the surface of slide lock 4 relative to the location of corresponding frame buttress 15 on slide lock 4 of second generation pistol 35. In addition, frame buttress 15A of the third generation pistol frame forms a different rearward angle, and contains additional frame material that extends further rearward within the frame 1 relative to second generation frame 10.

Upon discharge of pistols 35, 40, barrel unit 3B and slide 2 (e.g., engaged by abutment surfaces 11 and 56 forming the breech-lock mechanism) move rearward, where prior to barrel drop into recoil position, bottom surface 68 of front projection 52 clears frame buttress 15 and 15A. However, the extended buttress area of frame 15A interferes with correct rearward barrel motion, timing, and drop into recoil position and, consequently, interferes with slide travel.

An embodiment of the present invention provides for proper timing, barrel separation, and barrel drop in blank-fire operation by alteration of the barrel unit as illustrated in FIGS. 10-11. Initially, pistol 40 may include a blank-fire barrel unit 32B (FIG. 6B). The blank-fire barrel unit is similar to barrel unit 3B of pistol 40 described above and includes chamber portion 41B and barrel portion 43B. The chamber portion underside or bottom surface includes forward understation or projection 52 with bottom surface 12, and rear understation or projection 54 separated from front projection 52 by suitably dimensioned gap or recess 55. Front surface 60 of forward projection 52 includes upper shoulder 62 formed with and disposed below a bottom surface of barrel portion 43B, recess 64 defined in surface 60 below shoulder 62, and lower projection 66B disposed adjacent recess 64. Lower projection 66B includes front angled surface 14, and bottom surface 68 forming a front portion of front projection bottom surface 12. The chamber portion top surface includes abutment surface 11. The blank-fire barrel unit includes various modifications to at least abutment surface 11, front projection 52 and rear projection 54 as described below to enable and enhance repetitive blank fire.

Abutment surface 11 of barrel unit 32B is configured to obviate immediate contact between slide 2 and barrel unit 32B. In particular, abutment surface 11 includes a rearwardly inclined surface 57 angled in an approximate range of eight to forty-five degrees relative to a barrel unit longitudinal axis. This diminishes the effect of initial barrel unit/slide locking by enabling a predetermined distance of free travel of slide 2 rearward during recoil, thereby producing a delay between the slide rearward movement and contact with barrel inclined surface 57. For an example of this type of configuration, reference is made to the aforementioned Leiter patents.

Rear understation or projection 54 of barrel unit 32B is configured to allow for correct rear barrel drop. In particular, rear understation or projection 54 is configured with a shorter dimension by moving a forward most upwardly-angled surface 53 of the projection to the rear at an oblique angle, preferably approximating the forward angle configuration for projection 54 of barrel unit 3B. This effectively increases the dimensions of gap 55 and shortens the projection contact with the frame, thereby reducing the time and distance necessary for barrel unit 32B to drop downwardly into the rearward recoil/cartridge feeding position. Consequently, the amount of recoil force required to drive the slide and barrel unit rearwardly is reduced. Preferably, understation or projection 54 is shortened (or gap 55 is lengthened) by approximately 25% to 75% relative to barrel unit 3B (e.g., includes a reduced length in the approximate range of 0.075 to 0.225 inches). For an example of this type of configuration, reference is made to the aforementioned Leiter patents.

The combination of angled abutment surface 11 and shortened understation or projection 54 (or lengthened gap 55) assists pistol 40 to operate in a repetitive automatic manner with the barrel unit dropping to a cartridge feeding position at the appropriate time sequence. Barrel unit 32B may further include a restrictor element or occlusion 47 disposed at any suitable location (e.g., proximal or distal end, intermediate portion, etc.) within barrel portion 43B to generate sufficient back pressure upon firing of a blank cartridge to drive slide 2 and barrel unit 32B rearwardly, while the recoil spring mechanism returns slide 2 and barrel unit 32B to the battery position as described above.

In order to bypass frame buttress impediment 15A (FIG. 7) to achieve correct timing of barrel drop and separation from the slide for permitting repetitive blank-fire, front surface 14 and/or bottom surface 68 of lower projection 66B are configured to approximate the angular contour of frame buttress 15A (FIG. 7). The configurations may include angular and/or radial alterations of front and/or bottom surfaces 14, 68 relative to corresponding surfaces of barrel unit 3B. The particular angular or radial dimensions to be adopted by barrel unit 32B vary in accordance with specific firearms or pistols employed by the present invention embodiments, and is derived from the specific geometries of the pistol frame. By way of example, the height dimension of front surface 14 may be reduced to bypass frame buttress 15A (e.g., configure bottom surface 68 to project distally (or proximally) toward (or away from) chamber portion 41B). For example, front surface 14 of lower projection 66B may be configured (e.g., with a reduced height or thickness) to provide bottom surface 68 of lower projection 66B with an angled surface 70 disposed in an angular relation of approximately nine degrees relative to a longitudinal axis or centerline of the barrel unit. The angular relation may further be in the approximate range of one to fifteen degrees. The angle of angled surface 70 relative to the barrel unit longitudinal axis depends upon the nature and power of the blank ammunition employed, and the resultant velocity imparted to slide 2 of the pistol, since the velocity dictates the rapidity with which the barrel unit clears frame buttress impediment 15A (FIG. 7).

Alternatively, bottom surface 68 of lower projection 66B may include a curved configuration (or radial disposition). In particular, bottom surface 68 may include curved surface 72, preferably arcing outward from (e.g., convex configuration) chamber portion 41B and diminishing the thickness of surface 14. Curved surface 72 extends from the lower portion of front surface 14 (e.g., with minimal or no protrusion relative to bottom surface 68 of FIGS. 8-9) for an approximate length of approximately 0.200 to 1.600 inches. However, the length may vary depending upon the desired height or thickness of front surface 14. Curved surface 72 provides arcuate or curved relief to enable barrel unit 32B to bypass frame buttress 15A (FIG. 7).

Barrel unit 32B may further be configured to receive a laser device emitting a laser beam upon firearm actuation. This provides enhanced capabilities with respect to training and marksmanship applications. Referring to FIG. 12, barrel unit 32B is substantially similar to the barrel unit described above for FIGS. 10-11, and includes chamber portion 41B and barrel portion 43B. The chamber portion receives a blank cartridge and includes a bore area 58 to provide for expansion of combustion gases. The chamber portion underside or bottom surface includes forward understation or projection 52, and rear understation or projection 54 separated from front projection 52 by suitably dimensioned gap or recess 55, each as described above. The chamber portion top surface includes abutment surface 11 as described above. Barrel portion 43B includes muzzle 37 disposed at a barrel portion distal end, and a receiving chamber 50 disposed proximally of muzzle 37 to receive laser device 75 therein. Laser device 75 may be of the type disclosed in U.S. Pat. No. 6,322,365 (Shechter et al.) as described above.

Solid occluding element or occlusion 47 is disposed between receiving chamber 50 and bore area 58. Occlusion 47 prevents passage of a projectile through barrel unit 32B, and further prevents combustion gases from reaching laser device 75 disposed within muzzle 37. The combustion gases may damage the laser device and/or propel the laser device from the barrel unit. The laser device housing and internal mechanism are housed within receiving chamber 50. The laser device housing includes threading 46 disposed about the housing distal end external perimeter, while corresponding threads 36 are disposed about the internal perimeter of muzzle 37. Laser device 75 is removably affixed to the barrel unit by inserting the laser device into receiving chamber 50 and engaging muzzle threads 36 with laser device housing threads 46. Receiving chamber 50 includes transverse cross-sectional dimensions (e.g., diameter, etc.) in the approximate range of 0.312 to 0.375 inches, and a depth sufficient to provide occlusion 47 with longitudinal dimensions of approximately 0.100 to 0.750 inches. The particular dimensions of receiving chamber 50 depend upon the size and design of the laser device. The longitudinal depth of muzzle threads 36 is approximately 0.250 to 0.500 inches and depends upon the laser device geometries and the dimensional geometries of the barrel unit, where the combination of elements allows for the minimum occlusion dimension noted above. Further, muzzle threads 36 include a thread dimension and pitch matching that of laser device housing threads 46, and is preferably configured to include a thread dimension of approximately 7/16 of an inch with a pitch in the approximate range of 24 to 48 threads per inch. The particular specifications of thread dimensions and pitch are determined by the specific geometry of the laser device and the muzzle dimensions. In any case, muzzle threads 36 are configured to provide positive thread engagement without weakening the surrounding barrel unit material.

The operative principle of the present invention embodiments may be applied to any types or brands of firearms. The present invention embodiments provide a manner to enable proper timing of barrel/slide separation and barrel drop to permit reliable and repetitive blank-fire operation in various types and designs of breech-locked semiautomatic pistols.

It will be appreciated that the embodiments described above and illustrated in the drawings represent only a few of the many ways of implementing blank-firing barrels for semiautomatic pistols and method of repetitive blank fire.

The barrel units may be of any shape or size, and may be configured for any type or brand of firearm (e.g., semiautomatic pistol, hand-gun, etc.). The chamber and barrel portions may be of any size or shape, and occupy any desired portions of the barrel units. The abutment surfaces of the barrel units may be of any quantity, shape or size, and may be disposed at any suitable locations to engage the slide. The occlusion may be of any quantity, shape or size, may be constructed of any suitable materials, and may be disposed at any suitable locations (e.g., proximal end, distal end, intermediate portions, etc.) within the chamber and/or barrel portions of the barrel units.

The inclined surfaces of the barrel unit abutment surfaces may be oriented at any desired angles or angle ranges (e.g., preferably acute angles in the approximate range of one to ninety degrees, etc.) in any desired directions (e.g., rearward, etc.). The forward and rear understations or projections of the chamber portions may be of any quantity, shape or size and may be disposed at any suitable locations and/or arranged in any desired fashion. The gap between the forward and rear understations or projections may be of any desired dimensions and/or the dimensions of the rear understation or projection may be configured in any manner to bypass frame obstacles for suitable barrel drop.

Forward projection 25 of barrel unit 32A may be modified in any fashion to bypass support surface 27 or other obstacles of a firearm or frame. For example, the forward projection may be removed from the barrel unit. Further, projection 25 may include reduced dimensions or a modified configuration (e.g., curved, contoured, tapered, etc.) to bypass the support surface or other obstacle.

Forward projection 52 may be of any shape or size. The upper shoulder, recess and lower projection may be of any quantity, shape or size and disposed at any suitable locations. Lower projection 66B of barrel unit 32B may be modified in any fashion to bypass the frame buttress or other obstacles of a firearm or frame. For example, the height or thickness dimensions of front surface 14 may be adjusted in any fashion. Further, the surfaces of lower projection 66B may include any configurations (e.g., curved or arcuate toward any direction, contoured, tapered, tilted at any desired angles (e.g., preferably acute angles in the range of one to ninety degrees), scalloped or sinusoidal, substantially or entirely removed, etc.) to bypass the frame buttress or other obstacles. The various configurations may include any suitable dimensions or dimension ranges.

Moreover, the upper shoulder and recess may be modified in substantially the same manner as the lower projection. By way of example, the dimensions of one or more of these elements may be adjusted in any fashion. In addition, these elements may include various configurations (e.g., curved, contoured, tapered, tilted at any desired angles (e.g., preferably acute angles in the range of one to ninety degrees), scalloped or sinusoidal, substantially or entirely removed, etc.) to bypass obstacles for blank fire.

The threads of the barrel units may be of any quantity, shape or size, may include any desired dimensions, spacing or pitch, and may be disposed at any suitable locations (e.g., proximal end, distal end, intermediate portions, etc.) on or within the chamber and/or barrel portions of the barrel units to engage the laser device. The threads of the laser device may be of any quantity, shape or size, may include any desired dimensions, spacing or pitch, and may be disposed at any suitable locations on or within the housing (e.g., proximal end, distal end, intermediate portions, etc.). The laser device may be implemented by any conventional or other laser device to project a laser beam or other energy form (e.g., light, infrared, sound, etc.) from the barrel units in response to any conditions (e.g., trigger or firearm actuation, etc.). The laser device may be permanently or removably affixed to the barrel unit interior or exterior by any conventional or other securing techniques (e.g., fasteners, threaded engagement, friction fit, etc.). The receiving chambers may be of any quantity, shape or size to receive any portions of the laser device (e.g., the laser device may be partially or entirely disposed within the barrel units).

The barrel units of the present invention embodiments may be utilized in combination with any suitable type or brand of firearms to produce a firearm with repetitive blank fire capability. Further, the various configurations of the barrel unit elements (e.g., abutment surface, forward and rear projections, etc.) may be utilized by a barrel unit either individually, or in any desired combinations, to enable repetitive blank fire.

It is to be understood that the terms “top”, “bottom”, “front”, “rear”, “side”, “height”, “length”, “width”, “upper”, “lower”, “forward” and the like are used herein merely to describe points of reference and do not limit the present invention embodiments to any particular orientation or configuration.

The barrel units are not limited to the applications or firearms described above, but may be utilized to facilitate repetitive blank-fire in any types or brands of firearms.

From the foregoing description, it will be appreciated that the invention makes available novel blank-firing barrels for semiautomatic pistols and method of repetitive blank fire, wherein a forward under-portion of a barrel is configured in various manners to provide clearance to allow the barrel to bypass frame-mounted impediments to blank-fire.

Having described preferred embodiments of new and improved blank-firing barrels for semiautomatic pistols and method of repetitive blank fire, it is believed that other modifications, variations and changes will be suggested to those skilled in the art in view of the teachings set forth herein. It is therefore to be understood that all such variations, modifications and changes are believed to fall within the scope of the present invention as defined by the appended claims. 

1. A barrel unit for a firearm to enable repetitive blank fire comprising: a barrel portion; and a chamber portion disposed proximally of said barrel portion to receive a blank cartridge, wherein said chamber portion includes: a first projection disposed on a chamber portion bottom surface toward a barrel unit proximal end; and a second projection disposed on said chamber portion bottom surface toward said barrel portion, wherein said first and second projections are separated on said chamber portion bottom surface by a gap, and said chamber portion bottom surface extending from said barrel portion to said first projection is substantially planar with said barrel portion bottom surface.
 2. The barrel unit of claim 1, wherein said firearm includes a slide with a slide abutment surface, and said chamber portion further includes: a barrel abutment surface disposed on said chamber portion top surface toward said barrel portion, wherein said barrel abutment surface is angled to delay engagement by said slide abutment surface during recoil of said firearm.
 3. The barrel unit of claim 2, wherein said gap displaces said first projection from said second projection sufficiently to enable proper drop of said barrel unit in said firearm.
 4. The barrel unit of claim 1, wherein said barrel unit is configured for a Heckler and Koch type pistol.
 5. The barrel unit of claim 1, wherein said barrel portion includes an occlusion to prevent passage of combustion gases generated from discharge of said blank cartridge.
 6. The barrel unit of claim 1, wherein said barrel portion includes threading at a barrel portion distal end.
 7. The barrel unit of claim 1, further including a laser device at least partially disposed within said barrel portion to emit a laser beam in response to actuation of said firearm.
 8. The barrel unit of claim 7, wherein said barrel portion includes threading at a barrel portion distal end, and said laser device includes complementary threading to engage said barrel portion threading and secure said laser device to said barrel portion.
 9. A firearm for repetitive blank fire comprising: a frame; a slide mounted on said frame; and a barrel unit including: a barrel portion; and a chamber portion disposed proximally of said barrel portion to receive a blank cartridge, wherein said chamber portion includes: a first projection disposed on a chamber portion bottom surface toward a barrel unit proximal end; and a second projection disposed on said chamber portion bottom surface toward said barrel portion, wherein said first and second projections are separated on said chamber portion bottom surface by a gap, and said chamber portion bottom surface extending from said barrel portion to said first projection is substantially planar with said barrel portion bottom surface.
 10. A method of enabling repetitive blank fire within a firearm, wherein said firearm includes a barrel unit comprising a barrel portion and a chamber portion disposed proximally of said barrel portion to receive a blank cartridge, and wherein said chamber portion includes a first projection disposed on a chamber portion bottom surface toward a barrel unit proximal end and a second projection disposed on said chamber portion bottom surface toward said barrel portion and separated from said first projection by a gap, said method comprising: (a) configuring said chamber portion bottom surface extending from said barrel portion to said first projection to be substantially planar with said barrel portion bottom surface.
 11. The method of claim 10, wherein said firearm includes a slide with a slide abutment surface and said chamber portion further includes a barrel abutment surface disposed on said chamber portion top surface toward said barrel portion, said method further comprising: (b) configuring said barrel abutment surface to be angled to delay engagement by said slide abutment surface during recoil of said firearm.
 12. The method of claim 11, further comprising: (c) configuring said gap to displace said first projection from said second projection sufficiently to enable proper drop of said barrel unit in said firearm.
 13. The method of claim 10, further comprising: (b) preventing passage of combustion gases generated from discharge of said blank cartridge within said barrel portion via an occlusion.
 14. The method of claim 10, further comprising: (b) configuring said barrel portion to include threading at a barrel portion distal end.
 15. The method of claim 10, further comprising: (b) receiving a laser device at least partially within said barrel portion to emit a laser beam in response to actuation of said firearm.
 16. The method of claim 15, wherein said barrel portion includes threading at a barrel portion distal end and said laser device includes complementary threading, and step (b) further includes: (b.1) engaging said barrel portion threading with said laser device threading to secure said laser device to said barrel portion.
 17. A barrel unit for a firearm to enable repetitive blank fire comprising: a barrel portion; and a chamber portion disposed proximally of said barrel portion to receive a blank cartridge, wherein said chamber portion includes: a first projection disposed on a chamber portion bottom surface toward a barrel unit proximal end; and a second projection disposed on said chamber portion bottom surface toward said barrel portion, wherein said first and second projections are separated on said chamber portion bottom surface by a gap, and wherein said second projection includes a lower projection with a bottom surface projecting toward said chamber portion and forming a distal portion of a bottom surface of said second projection.
 18. The barrel unit of claim 17, wherein said lower projection bottom surface is oriented at an angle relative to a longitudinal axis of said barrel unit.
 19. The barrel unit of claim 17, wherein said lower projection bottom surface includes a curved configuration.
 20. The barrel unit of claim 17, wherein said firearm includes a slide with a slide abutment surface, and said chamber portion further includes: a barrel abutment surface disposed on said chamber portion top surface toward said barrel portion, wherein said barrel abutment surface is angled to delay engagement by said slide abutment surface during recoil of said firearm.
 21. The barrel unit of claim 20, wherein said gap displaces said first projection from said second projection sufficiently to enable proper drop of said barrel unit in said firearm.
 22. The barrel unit of claim 17, wherein said barrel unit is configured for a GLOCK type pistol.
 23. The barrel unit of claim 17, wherein said barrel portion includes an occlusion to prevent passage of combustion gases generated from discharge of said blank cartridge.
 24. The barrel unit of claim 17, wherein said barrel portion includes threading at a barrel portion distal end.
 25. The barrel unit of claim 17, further including a laser device at least partially disposed within said barrel portion to emit a laser beam in response to actuation of said firearm.
 26. The barrel unit of claim 25, wherein said barrel portion includes threading at a barrel portion distal end, and said laser device includes complementary threading to engage said barrel portion threading and secure said laser device to said barrel portion.
 27. A firearm for repetitive blank fire comprising: a frame; a slide mounted on said frame; and a barrel unit including: a barrel portion; and a chamber portion disposed proximally of said barrel portion to receive a blank cartridge, wherein said chamber portion includes: a first projection disposed on a chamber portion bottom surface toward a barrel unit proximal end; and a second projection disposed on said chamber portion bottom surface toward said barrel portion, wherein said first and second projections are separated on said chamber portion bottom surface by a gap, and wherein said second projection includes a lower projection with a bottom surface projecting distally toward said chamber portion and forming a distal portion of a bottom surface of said second projection.
 28. A method of enabling repetitive blank fire within a firearm, wherein said firearm includes a barrel unit comprising a barrel portion and a chamber portion disposed proximally of said barrel portion to receive a blank cartridge, and wherein said chamber portion includes a first projection disposed on a chamber portion bottom surface toward a barrel unit proximal end and a second projection disposed on said chamber portion bottom surface toward said barrel portion and separated from said first projection by a gap, said method comprising: (a) configuring said second projection to include a lower projection with a bottom surface projecting distally toward said chamber portion and forming a distal portion of a bottom surface of said second projection.
 29. The method of claim 28, wherein step (a) further includes: (a.1) configuring said lower projection bottom surface to be oriented at an angle relative to a longitudinal axis of said barrel unit.
 30. The method of claim 28, wherein step (a) further includes: (a.1) configuring said lower projection bottom surface to include a curved configuration.
 31. The method of claim 28, wherein said firearm includes a slide with a slide abutment surface and said chamber portion further includes a barrel abutment surface disposed on said chamber portion top surface toward said barrel portion, said method further comprising: (b) configuring said barrel abutment surface to be angled to delay engagement by said slide abutment surface during recoil of said firearm.
 32. The method of claim 31, further comprising: (c) configuring said gap to displace said first projection from said second projection sufficiently to enable proper drop of said barrel unit in said firearm.
 33. The method of claim 28, further comprising: (b) preventing passage of combustion gases generated from discharge of said blank cartridge within said barrel portion via an occlusion.
 34. The method of claim 28, further comprising: (b) configuring said barrel portion to include threading at a barrel portion distal end.
 35. The method of claim 28, further comprising: (b) receiving a laser device at least partially within said barrel portion to emit a laser beam in response to actuation of said firearm.
 36. The method of claim 35, wherein said barrel portion includes threading at a barrel portion distal end and said laser device includes complementary threading, and step (b) further includes: (b.1) engaging said barrel portion threading with said laser device threading to secure said laser device to said barrel portion.
 37. The barrel unit of claim 18, wherein said angle relative to said longitudinal axis of said barrel unit is in the range of one to fifteen degrees.
 38. The method of claim 29, wherein said angle relative to said longitudinal axis of said barrel unit is in the range of one to fifteen degrees. 